Ci/verify load errors

.github/workflows/ios.yml

@@ -5,6 +5,7 @@ on:
     branches: [ "main" ]
   pull_request:
     branches: [ "main" ]
+  workflow_dispatch:
 
 jobs:
   build:

PayForMe.xcodeproj/project.pbxproj

@@ -7,6 +7,7 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		C34C21CC3AD72833B6C06C9D /* LoadErrorTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = CD167A293B2F0746C0A09C2E /* LoadErrorTests.swift */; };
 		481FB4FB23E964C8003BD108 /* ProjectManager.swift in Sources */ = {isa = PBXBuildFile; fileRef = 481FB4FA23E964C8003BD108 /* ProjectManager.swift */; };
 		481FB4FD23EAD78F003BD108 /* AddProjectManualViewModel.swift in Sources */ = {isa = PBXBuildFile; fileRef = 481FB4FC23EAD78F003BD108 /* AddProjectManualViewModel.swift */; };
 		489995DA23F6EC6F008B7E38 /* OnboardingView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 489995D923F6EC6F008B7E38 /* OnboardingView.swift */; };
@@ -88,6 +89,7 @@
 /* End PBXContainerItemProxy section */
 
 /* Begin PBXFileReference section */
+		CD167A293B2F0746C0A09C2E /* LoadErrorTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = LoadErrorTests.swift; sourceTree = "<group>"; };
 		0865D2DAF541B24078D1DC41 /* TestHelpers.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = TestHelpers.swift; sourceTree = "<group>"; };
 		143F41EE78329905894C8A29 /* BalanceCalculationTests.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = BalanceCalculationTests.swift; sourceTree = "<group>"; };
 		316FBA7C0CE4ABB51EC2A121 /* NetworkRequestTests.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = NetworkRequestTests.swift; sourceTree = "<group>"; };
@@ -228,6 +230,7 @@
 			isa = PBXGroup;
 			children = (
 				654754E32528B29F00A82EB6 /* AddProjectManuallyTests.swift */,
+				CD167A293B2F0746C0A09C2E /* LoadErrorTests.swift */,
 				654754E52528B29F00A82EB6 /* Info.plist */,
 				6523FC4B25580EEF00BCD843 /* UrlExtensionsTests.swift */,
 				0865D2DAF541B24078D1DC41 /* TestHelpers.swift */,
@@ -544,6 +547,7 @@
 			buildActionMask = 2147483647;
 			files = (
 				654754E42528B29F00A82EB6 /* AddProjectManuallyTests.swift in Sources */,
+				C34C21CC3AD72833B6C06C9D /* LoadErrorTests.swift in Sources */,
 				6523FC4C25580EEF00BCD843 /* UrlExtensionsTests.swift in Sources */,
 				57BC8D25B91CE40F4669650C /* TestHelpers.swift in Sources */,
 				D279295CFA25D9CC69C6F27C /* BillTests.swift in Sources */,

PayForMe/Services/NetworkService.swift

@@ -8,6 +8,49 @@
 import Combine
 import Foundation
 
+/// Why loading a project's data failed.
+///
+/// The load publishers used to declare `Never` as their failure type, which
+/// left everything upstream unable to tell "this project is empty" from "the
+/// server rejected us". Changing a project's password on the server therefore
+/// showed empty lists and no explanation at all (#37).
+enum LoadError: Error, Equatable, Identifiable {
+    /// Credentials rejected. Usually the project password was changed on the
+    /// server after it was added here.
+    case unauthorized
+    case notFound
+    case http(Int)
+    /// No usable connection, or a response that was not HTTP at all.
+    case connection
+    /// The server answered, but not with something we could decode.
+    case invalidResponse
+
+    var id: String { String(describing: self) }
+
+    init(statusCode: Int) {
+        switch statusCode {
+        case 401, 403:
+            self = .unauthorized
+        case 404:
+            self = .notFound
+        default:
+            self = .http(statusCode)
+        }
+    }
+
+    init(_ error: Error) {
+        switch error {
+        case let serverError as LoadError:
+            self = serverError
+        case is URLError:
+            self = .connection
+        default:
+            // Decoding failed: the server answered, we just could not read it.
+            self = .invalidResponse
+        }
+    }
+}
+
 class NetworkService {
     static let shared = NetworkService()
 
@@ -34,16 +77,25 @@ class NetworkService {
 
     let networkActivityPublisher = PassthroughSubject<Bool, Never>()
 
-    func loadBillsPublisher(_ project: Project) -> AnyPublisher<[Bill], Never> {
+    /// Turns a response into its body or into a typed failure. Both cases used
+    /// to collapse into "no value emitted", which is precisely what made a
+    /// rejected password indistinguishable from an empty project.
+    private static func validate(_ data: Data, _ response: URLResponse) throws -> Data {
+        guard let httpResponse = response as? HTTPURLResponse else {
+            throw LoadError.connection
+        }
+        guard httpResponse.statusCode == 200 else {
+            throw LoadError(statusCode: httpResponse.statusCode)
+        }
+        return data
+    }
+
+    func loadBillsPublisher(_ project: Project) -> AnyPublisher<[Bill], LoadError> {
         let request = buildURLRequest("bills", params: [:], project: project)
         return URLSession.shared.dataTaskPublisher(for: request)
-            .compactMap { data, response -> Data? in
-                guard let httpResponse = response as? HTTPURLResponse else { print("Network Error"); return nil }
-                guard httpResponse.statusCode == 200 else { print("Network Error: Status code: \(httpResponse.statusCode) \(httpResponse.description)"); return nil }
-                return data
-            }
+            .tryMap { data, response in try NetworkService.validate(data, response) }
             .decode(type: [Bill].self, decoder: decoder)
-            .replaceError(with: [])
+            .mapError { LoadError($0) }
             .map {
                 $0.sorted {
                     if let l1 = $0.lastchanged,
@@ -57,16 +109,12 @@ class NetworkService {
             .eraseToAnyPublisher()
     }
 
-    func loadMembersPublisher(_ project: Project) -> AnyPublisher<[Int: Person], Never> {
+    func loadMembersPublisher(_ project: Project) -> AnyPublisher<[Int: Person], LoadError> {
         let request = buildURLRequest("members", params: [:], project: project)
         return URLSession.shared.dataTaskPublisher(for: request)
-            .compactMap { data, response -> Data? in
-                guard let httpResponse = response as? HTTPURLResponse else { print("Network Error"); return nil }
-                guard httpResponse.statusCode == 200 else { print("Network Error: Status code: \(httpResponse.statusCode) \(httpResponse.description)"); return nil }
-                return data
-            }
+            .tryMap { data, response in try NetworkService.validate(data, response) }
             .decode(type: [Person].self, decoder: decoder)
-            .replaceError(with: [])
+            .mapError { LoadError($0) }
             .map {
                 members in
                 let filtered = members.filter {

PayForMe/Services/ProjectManager.swift

@@ -26,6 +26,11 @@ class ProjectManager: ObservableObject {
 
     @Published var openedByURL: URL?
 
+    /// The last failure while loading bills and members, or nil after a load
+    /// that worked. Set so the UI can say something instead of showing lists
+    /// that are empty for no visible reason (#37).
+    @Published var loadingError: LoadError?
+
     private init() {
         print("init")
         projects = storageService.loadProjects()
@@ -80,8 +85,15 @@ class ProjectManager: ObservableObject {
             .receive(on: DispatchQueue.main)
             .handleEvents(receiveCancel: invokeCompletionOnce)
             .sink(
-                receiveCompletion: { _ in invokeCompletionOnce() },
+                receiveCompletion: { [weak self] result in
+                    if case let .failure(error) = result {
+                        self?.loadingError = error
+                    }
+                    invokeCompletionOnce()
+                },
                 receiveValue: { [weak self] project in
+                    // A load that worked clears whatever went wrong last time.
+                    self?.loadingError = nil
                     self?.currentProject = project
                     invokeCompletionOnce()
                 }

PayForMe/Strings/cs.lproj/Localizable.strings

@@ -150,3 +150,10 @@
 "member_error_forbidden" = "To obvykle vyžaduje práva správce projektu. Sdílené heslo projektu může umožňovat jen přístup účastníka.";
 "member_error_network" = "Není spojení se serverem. Zkontrolujte síť a zkuste to znovu.";
 "member_error_generic" = "Server odmítl požadavek (HTTP %d).";
+
+"Could not load project" = "Projekt se nepodařilo načíst";
+"load_error_unauthorized" = "Server odmítl uložené heslo. Pokud se heslo projektu změnilo, přidej projekt znovu s novým heslem.";
+"load_error_not_found" = "Server tento projekt nezná. Možná byl smazán nebo je špatné ID projektu.";
+"load_error_connection" = "Žádné spojení se serverem. Zkontroluj síť a zkus to znovu.";
+"load_error_invalid_response" = "Odpověď serveru nelze přečíst. Možná nejde o server Cospend ani iHateMoney.";
+"load_error_generic" = "Server projekt neodeslal (HTTP %d).";

PayForMe/Strings/de.lproj/Localizable.strings

@@ -154,3 +154,10 @@
 "member_error_forbidden" = "Für den Erfolg sind meist Maintainer-Rechte am Projekt nötig. Du kannst diese Berechtigungen jederzeit erteilen, indem du die Einstellungen des Freigabelinks in Cospend (deiner Nextcloud-App) änderst.";
 "member_error_network" = "Keine Verbindung zum Server. Bitte Netzwerk prüfen und erneut versuchen.";
 "member_error_generic" = "Der Server hat die Anfrage abgelehnt (HTTP %d).";
+
+"Could not load project" = "Projekt konnte nicht geladen werden";
+"load_error_unauthorized" = "Der Server hat das gespeicherte Passwort abgelehnt. Wurde das Projektpasswort geändert, füge das Projekt mit dem neuen Passwort erneut hinzu.";
+"load_error_not_found" = "Der Server kennt dieses Projekt nicht. Möglicherweise wurde es gelöscht oder die Projekt-ID stimmt nicht.";
+"load_error_connection" = "Keine Verbindung zum Server. Bitte prüfe dein Netzwerk und versuche es erneut.";
+"load_error_invalid_response" = "Die Antwort des Servers war nicht lesbar. Möglicherweise ist es kein Cospend- oder iHateMoney-Server.";
+"load_error_generic" = "Der Server hat das Projekt nicht herausgegeben (HTTP %d).";

PayForMe/Strings/en.lproj/Localizable.strings

@@ -157,3 +157,10 @@
 "member_error_forbidden" = "This usually requires maintainer rights for the project. You can grant those at any time by changing the share-link's settings in Cospend (your Nextcloud-App).";
 "member_error_network" = "No connection to the server. Please check your network and try again.";
 "member_error_generic" = "The server rejected the request (HTTP %d).";
+
+"Could not load project" = "Could not load project";
+"load_error_unauthorized" = "The server rejected the stored password. If the project password was changed, add the project again with the new one.";
+"load_error_not_found" = "The server does not know this project. It may have been deleted, or the project id may be wrong.";
+"load_error_connection" = "No connection to the server. Please check your network and try again.";
+"load_error_invalid_response" = "The server's answer could not be read. It may not be a Cospend or iHateMoney server.";
+"load_error_generic" = "The server refused to send the project (HTTP %d).";

PayForMe/Strings/es.lproj/Localizable.strings

@@ -157,3 +157,10 @@
 "Enter invite link" = "Introducir el enlace de invitación";
 "invite_link_hint" = "Pega el enlace de invitación completo. El servidor y el proyecto se detectan automáticamente.";
 "Server returned an invalid HTTP response" = "El servidor devolvió una respuesta HTTP no válida";
+
+"Could not load project" = "No se pudo cargar el proyecto";
+"load_error_unauthorized" = "El servidor rechazó la contraseña guardada. Si se cambió la contraseña del proyecto, añádelo de nuevo con la nueva.";
+"load_error_not_found" = "El servidor no conoce este proyecto. Puede que se haya eliminado o que el identificador sea incorrecto.";
+"load_error_connection" = "Sin conexión con el servidor. Comprueba tu red e inténtalo de nuevo.";
+"load_error_invalid_response" = "No se pudo leer la respuesta del servidor. Puede que no sea un servidor Cospend o iHateMoney.";
+"load_error_generic" = "El servidor se negó a enviar el proyecto (HTTP %d).";

PayForMe/Strings/fr.lproj/Localizable.strings

@@ -157,3 +157,10 @@
 "Enter invite link" = "Saisir le lien d'invitation";
 "invite_link_hint" = "Collez le lien d'invitation complet. Le serveur et le projet sont détectés automatiquement.";
 "Server returned an invalid HTTP response" = "Le serveur a renvoyé une réponse HTTP non valide";
+
+"Could not load project" = "Impossible de charger le projet";
+"load_error_unauthorized" = "Le serveur a refusé le mot de passe enregistré. Si le mot de passe du projet a changé, ajoutez à nouveau le projet avec le nouveau.";
+"load_error_not_found" = "Le serveur ne connaît pas ce projet. Il a peut-être été supprimé, ou l'identifiant est incorrect.";
+"load_error_connection" = "Pas de connexion au serveur. Vérifiez votre réseau et réessayez.";
+"load_error_invalid_response" = "La réponse du serveur est illisible. Ce n'est peut-être pas un serveur Cospend ou iHateMoney.";
+"load_error_generic" = "Le serveur a refusé d'envoyer le projet (HTTP %d).";

PayForMe/Strings/ru.lproj/Localizable.strings

@@ -156,3 +156,10 @@
 "member_error_forbidden" = "Обычно для этого нужны права сопровождающего проекта. Пароль общего доступа может давать только права участника.";
 "member_error_network" = "Нет соединения с сервером. Проверьте сеть и повторите попытку.";
 "member_error_generic" = "Сервер отклонил запрос (HTTP %d).";
+
+"Could not load project" = "Не удалось загрузить проект";
+"load_error_unauthorized" = "Сервер отклонил сохранённый пароль. Если пароль проекта изменился, добавьте проект заново с новым паролем.";
+"load_error_not_found" = "Сервер не знает этот проект. Возможно, он удалён или указан неверный идентификатор.";
+"load_error_connection" = "Нет соединения с сервером. Проверьте сеть и попробуйте снова.";
+"load_error_invalid_response" = "Не удалось прочитать ответ сервера. Возможно, это не сервер Cospend или iHateMoney.";
+"load_error_generic" = "Сервер отказался передать проект (HTTP %d).";

PayForMe/Views/ContentView.swift

@@ -46,6 +46,28 @@ struct ContentView: View {
                 manager.loadBillsAndMembers()
             }
         }
+        // Without this the app just shows empty lists when the server turns us
+        // away — the complaint behind #37.
+        .alert(item: $manager.loadingError) { error in
+            Alert(title: Text("Could not load project"),
+                  message: Text(Self.message(for: error)),
+                  dismissButton: .default(Text("OK")))
+        }
+    }
+
+    static func message(for error: LoadError) -> String {
+        switch error {
+        case .unauthorized:
+            return NSLocalizedString("load_error_unauthorized", comment: "Loading failed because the credentials were rejected")
+        case .notFound:
+            return NSLocalizedString("load_error_not_found", comment: "Loading failed because the project does not exist on the server")
+        case .connection:
+            return NSLocalizedString("load_error_connection", comment: "Loading failed because the server could not be reached")
+        case .invalidResponse:
+            return NSLocalizedString("load_error_invalid_response", comment: "Loading failed because the server's answer could not be read")
+        case let .http(code):
+            return String(format: NSLocalizedString("load_error_generic", comment: "Loading failed with an HTTP status code"), code)
+        }
     }
 
     var tabBar: some View {